1. Field of the Invention
The present invention relates to a method of manufacturing 2',3'-dideoxy-2',3'-didehydronucleosides.
2. Description of the Related Art
2',3'-dideoxy-2',3'-didehydronuclesides are resistant to viruses and cancer. Further, they are known as anti-HIV agents and are, therefore, useful as raw materials for the production of medicines. They are represented by the following general formula (I): ##STR1## where R.sup.1 is a silyl protective group, and B is a purine base or a pyrimidine base.
Various methods of manufacturing 2',3'-dideoxy2',3'-didehydronucleosides are known. Methods wherein a ribonucleoside is used are described in The Journal of the Organic Chemistry 39, 30 (1974), The Journal of the Organic Chemistry 53, 5170 (1988), and The Journal of the Organic Chemistry 54, 2217 (1989). Methods wherein a 2'-deoxynucleoside is used are disclosed in The Journal of the American Chemical Society 88, 1549 (1966) and The Journal of the Organic Chemistry 32, 817 (1967).
Most of the known methods described above comprise many steps, and require the use of costly reagents as raw materials. They achieve but a low yield and are not economical. Thus, they are unfit for industrial use.